A recent study had shown that calcium channel blockers, a class of drugs commonly used to treat hypertension, were associated with a two-fold increase in risk of breast cancer in women who used them for 10 or more years. If true, this finding raises considerable concern about the use of these drugs in women. But those concerns have largely been put to rest by our prospective cohort study which has been following more than 50,000 women at increased breast cancer risk since 2003. Although 1372 women developed invasive breast cancer, women who used calcium channel blockers or other classes of antihypertensive drugs had the same breast cancer risk as women who did not use the drugs. As part of a series of international consortia investigating the determinants of cancer risk we have identified a set of genetic variants associated with bladder cancer, and begun to identify the dietary determinants of bladder cancer. In addition we have published as series of studies investigating both the genetic and environmental determinants of breast cancer risk.